1. Field of the Invention
The present invention relates generally to a diagnostic assay and, more particularly, an assay for measuring cell-mediated immune reactivity. Even more particularly, the present invention provides an assay and a kit for measuring a cell-mediated response to an antigen using whole blood or other suitable biological sample. The assay may be conducted using ligands to immune effector molecules or at the nucleic acid level, screening for expression of genes encoding the immune effector molecules. The assay is useful in therapeutic and diagnostic protocols for human, livestock and veterinary and wild life applications.
2. Description of the Prior Art
Bibliographic details of references provided in the subject specification are listed at the end of the specification.
Reference to any prior art in this specification is not, and should not be taken as, an acknowledgment or any form of suggestion that this prior art forms part of the common general knowledge in any country.
Measurement of cell-mediated immune (CMI) responses is important for immune diagnosis of many infectious and autoimmune diseases, as a marker for immunocompetence, and for detection of T-cell responses to endogenous and exogenous antigens (i.e. vaccines).
Current methods for detecting CMI responses include skin tests measuring both immediate and delayed type hypersensitivity, lymphocyte proliferation assays and measurement of cytokines produced by purified mononuclear cells cultured with antigen.
Most in vitro methods for detecting CMI responses involve the purification of lymphocytes from whole blood, culturing these lymphocytes with an antigen for periods from 12 hours to 6 days and then detecting T-cell reactivity to the antigen. Older, established methods, such as the proliferation assay, use the uptake of radioactive isotopes by dividing T-cells as a marker for CMI reactivity. More recently, techniques such as a single cell assay (ELISpot) have been used to detect the number of T-cells producing certain cytokines in response to the antigenic stimulation.
Despite the existence of the previously used assays for measuring CMI responsiveness, the practical limitations of easily and accurately measuring CMI responses have hitherto precluded large scale adoption of these assays in standard and routine medical practice in the diagnosis of infectious disease, autoimmune disease and oncology.